Introduction

SOSfinder gives you Secretary of State business-entity data for all 50 states through a single REST endpoint — entity status, registered agent, formation date, and more.

Every lookup goes through one unified endpoint. Pass a business name and a state, and SOSfinder returns the best match plus similar filings in one consistent schema for every state.

Quickstart

Authenticate with your secret key from the server side and GET /search with a state and a business name.

curl 'https://api.sosfinder.com/search?state=WY&business_name=Acme%20LLC' \
  -H "x-api-key: $SOS_API_KEY"

Next steps

Authentication

Get a key and call the API securely.

API credits

How lookups are counted and billed.

Entity search

The full request and response reference.

Rate limits

Limits, headers, and best practices.

Stuck on something the docs don’t cover? Email support@sosfinder.com and we’ll help you out.